1 files changed, 22 insertions, 0 deletions
diff --git a/pkg/tcpip/checker/checker.go b/pkg/tcpip/checker/checker.go
index 2f15bf1f1..885d773b0 100644
--- a/pkg/tcpip/checker/checker.go
+++ b/pkg/tcpip/checker/checker.go
@@ -33,6 +33,9 @@ type NetworkChecker func(*testing.T, []header.Network)
 // TransportChecker is a function to check a property of a transport packet.
 type TransportChecker func(*testing.T, header.Transport)
 
+// ControlMessagesChecker is a function to check a property of ancillary data.
+type ControlMessagesChecker func(*testing.T, tcpip.ControlMessages)
+
 // IPv4 checks the validity and properties of the given IPv4 packet. It is
 // expected to be used in conjunction with other network checkers for specific
 // properties. For example, to check the source and destination address, one
@@ -158,6 +161,19 @@ func FragmentFlags(flags uint8) NetworkChecker {
 	}
 }
 
+// ReceiveTOS creates a checker that checks the TOS field in ControlMessages.
+func ReceiveTOS(want uint8) ControlMessagesChecker {
+	return func(t *testing.T, cm tcpip.ControlMessages) {
+		t.Helper()
+		if !cm.HasTOS {
+			t.Fatalf("got cm.HasTOS = %t, want cm.TOS = %d", cm.HasTOS, want)
+		}
+		if got := cm.TOS; got != want {
+			t.Fatalf("got cm.TOS = %d, want %d", got, want)
+		}
+	}
+}
+
 // TOS creates a checker that checks the TOS field.
 func TOS(tos uint8, label uint32) NetworkChecker {
 	return func(t *testing.T, h []header.Network) {
@@ -754,3 +770,9 @@ func NDPNSTargetAddress(want tcpip.Address) TransportChecker {
 		}
 	}
 }
+
+// NDPRS creates a checker that checks that the packet contains a valid NDP
+// Router Solicitation message (as per the raw wire format).
+func NDPRS() NetworkChecker {
+	return NDP(header.ICMPv6RouterSolicit, header.NDPRSMinimumSize)
+}